The present invention concerns systems for refrigerating containers (particularly transcontainers) containing perishable goods which must be maintained at a sufficiently low temperature, either during storage or during transportation of the goods, primarily on board ships but also by other means, for example on board refrigerated lorries.
The principle of refrigerating such containers is that their interior is connected to a refrigerating installation which blows for example cold air into the container. A cold air injection opening and a cold air discharge opening are provided in each container and conduits are connected to the containers at such openings, for connection to a refrigeration system which is common to all the containers.
As a single refrigeration system (for example a cold air reservoir) is provided for a plurality of containers, generally, when the containers arrive at their storage location, each of the containers is connected to an opening provided in a cold air circulation duct which has a certain number of openings distributed along its length. It is therefore necessary to provide releasable coupling means for coupling between this system and each container; such means must be easy to use and obviously must ensure a good seal, in order to prevent any leakage of cold air to the exterior of the refrigeration circuit formed by the refrigeration system, the conduits carrying cold air, the container and the coupling means. It is also necessary to provide that such coupling can always be effected with a good sealing action and without difficulty, even if the containers are not always positioned at a precise distance from the common refrigeration system.